1. Field of the Invention
This invention relates to a machine for supplying and placing electronic chips such as resistors, capacitors, coils, diodes and transistors, and more particularly to a machine for placing the electronic chips and test resistance, capacitance, or polarity thereof.
2. Description of the Prior Art
Heretofore, when testing leadless electronic chips immediately before placing the electronic chips at a selected position on a printed circuit (P.C.) board, a particular process for testing the chips is required. Namely, a chip-placement machine of the prior art is required to have a special process in which, for instance, the chip in question is shifted by using another driving means to a check position with the chip being held by a suction nozzle, and the chip is shifted back to a placement position after testing. Therefore, there are the drawbacks that the structure of the machine is complicated and that the manufacturing cost is high.
Moreover, in the case of testing a small electronic chip, both electrodes of the chip 1 are short-circuited through the portions 3 of a suction nozzle 2 which is made of a conductive metal as shown in FIG. 6. Therefore, it is required that the suction nozzle 2 has to be separated from the chip 1 when testing the same. Accordingly, as shown in FIGS. 7A to 7G, an operational process of the suction nozzle 2 and a pair of probes 20a, 20b for testing are operated as follows: descent of the nozzle (7B), application of the probes (7C), ascent of the nozzle and test (7D), descent of the nozzle and suction (7E), withdrawal of the probes (7F), and ascent of the nozzle (7G). Thus, one cycle of the operational process required a long period of time so that there is a further disadvantage that productivity is decreased when the testing function is incorporated into the placement machine.